It's the dawn of a big, new, fantastical world at House Theatre

The program of the House Theatre of Chicago's expansive and arresting new production, "The Iron Stag King, Part One" comes replete with a hand-drawn map of a fantastical land, not so different, really, from the maps that J.R.R. Tolkien prepared for the published versions of "The Hobbit" and "The Lord of the Rings." At the House Theatre, the glossy cartography depicts not Tolkien's Middle Earth, but a fictive island replete with distinct and enigmatic lands: Grass, Salt, Glaze, Arcadia.

Authors Nathan Allen and Chris Mathews are openly borrowing from Tolkien given that their show, the first in an intended trilogy, is formed around a journey and a quest of a group of companions, of constantly shifting loyalties, through a mythic landscape of indeterminate time, place and humanity. But he's hardly the only influence on this ambitious and ebullient piece of original theater. The story, a kind of mythological mashup, begins with the secret removal of a baby on the antlers of the titular beast, who then grows up like Sophocles' Oedipus, ignorant of his true identity. Once people find where this Casper Kent (Brandon Ruiter) is, they come to get him and he's got to figure out whom to follow.

The hero of this tale seeks to lift up something called the hammer, which has lot in common with King Arthur's Excalibur. There are Shakespearean riffs on the limits of benign monarchical rule and, given, the main themes of revolution followed by divided republicanism, even a few nods to E.L. Doctorow. Allen and Mathews may love comic books and fantasy drama, but they're romantic, moralist Americans at heart, wearing their hearts and boyish excitement on their sleeves, even when that leads them to overplay their metaphoric hands. They've even got puppets here that have something in common with the critters of "War Horse." And neither Tolkien nor Doctorow had the recorded, creepily authoritarian voice of Tracy Letts filling us in on the earth-cracking narrative so far, like a Hollywood narrator gone to hell.

Those whose eyes glaze over at fantasy gaming and fiction will likely want "The Iron Stag King" to butt out long before its two and a half hours are up, if they even want to wrestle with its antlers at all. The show, which premiered Sunday night, is at least 15 minutes too long and, more importantly, its initially zestful narrative drive gets overwhelmed in the second act by flashbacks and digressions that sideline the crucial main intention. Lose the overarching point in a world as complex as this one, and you lose your audience. It seems that Allen and Mathews were unsure about how whole hog to go into their mythological realm — the House Theatre's house style generally is to acknowledge artifice and the viewer, but this show does so only intermittently, when it needs to forge a more consistent style of engagement and cue the audience by making clear how seriously it wants to take itself. Fantasy-loving folks are sticklers for rules. Allen and Mathews seem a tad self-conscious about being grown men delving into this kind of stuff. They should banish that. It's a free country here, if not in all the corners of the island of their invention.

House Theatre always has been about young audiences and fantastical sagas, even if the creatives involved are not so young anymore. "Iron Stag King," which features the return to House of the story-spinning actor Cliff Chamberlain, among many other pleasures, is an epic, highly entertaining affair of warring snakes, dodgy narrators and superhuman combat skills, all staged in a space about the size of the wrestling ring. The fights, choreographed by Justin Verstraete, are intense indeed. And even if the narrative is not easy to fully grasp on a single viewing (the same could be said of Tolkien), there's no doubt that Allen and Mathews have painted a picture of the world some of us children used to see when we closed our eyes at night.

For all the testosterone on display by juicy actors like Walter Briggs and James D. Farruggio, there are plenty of powerful women in the story, played by the likes of Paige Collins and the terrific Kay Kron, taking on males both human and mythical and hanging with all kinds of wolves. As the main villain of the piece (maybe), Joey Steakley comes with a very interesting, faux-colonialist nastiness, part of a theatrical map with many overlapping lands indeed, evocatively designed by Collette Pollard with puppets and other specialties by Lee Keenan.

If you can give yourself over fully to the yarn and the landscape (and House should keep working, and cutting, to remove all impediments), the question of who gets to raise the hammer and what that means for the regular folks will be a delightful escape from reality, even if that very same question currently fills the airwaves.